1. Field of the Invention
The invention is directed to tooling for machining operations and, more particularly, directed to a toolholder assembly for precisely locating a toolholder at a selected location within the toolholder assembly during a machining operation.
2. Description of The Related Art
Minimizing the down time of a machine tool in a production environment is critical to the success of a machining facility. Historically, one major contribution to such down time was the time needed to change damaged or worn out cutting tools used by the machine tool. A cutting tool is held by a toolholder, which is typically mounted within a tool support member secured to a machine tool. When the cutting tool must be replaced, the entire toolholder with the cutting tool attached thereto is removed from the support member. A number of couplings are designed to permit quick connecting and disconnecting of the toolholder to and from the tool support member to expedite the tool changing process. One such device is described in U.S. Pat. No. 4,736,659 entitled “Toolholder Assembly for Holding a Toolholder Shank.” This patent is co-owned by the Assignee of the present application and is hereby incorporated by reference. The toolholder assembly described in that patent utilizes two locking balls which are urged radially outwardly within a tool support member to engage apertures on the shank of a toolholder. While this arrangement is efficient and permits a toolholder to be removed or secured to a tool support member in a short amount of time, the design of this arrangement may limit its application to tool support members having radial access. Many industrial applications require the use of a tool support member having rear access.
U.S. Pat. No. 5,279,194 entitled “Ball Lock Assembly Without a Canister” is owned by the Assignee of the present application and is hereby incorporated by reference. While this assembly provides for rear access, actuation of the lock rod therein is achieved through multiple rotations of the torque nut and it is difficult to apply a given pull-back force.
In addition to a tool support member having rear access for actuation, a further object of the subject invention is to provide a repeatable maximum pull-back force on the lock rod with a minimum rotation of a rear end torque nut.